Method of making spring lock nuts



METHOD OF MAKING SPRING LOCK NUTS Filed May 27, 1955 54 41. EL WW A TTORNEY.

Patented Mar. 31, 1936 2,035,859 METHOD oF-mxnvo srame men more William A. Bergstrom, Oakland, (la-lit. assignor to Renchtite Spring Nut Company, San Francisco, Galih, a corporation of California Application May 27, 1935, Serial No. 23,029

a (or. -86) This invention relates to spring lock nuts, and to the method of g them.

An object of my invention is the provision of nuts which, when applied, are self-locmng by 5 their spring action and which may be used a plurallty of times without permanent set or deformation taking place therein while they are in functioning position, that is, while under normal strain.

method of making such spring lock nuts.

Other objects of the invention will be apparcut on reading the appended specification.

Referring to the drawing which forms a part this speclfication,

Fig. 1 is an elevation of the nut itself; and

Fig. 2 is a sectional view showing the nut in applied position.

The nut it follows theusual standards as to its various ensions for practical purposes, and it may be of any desired shape, that is, square or I hexagonal.

It difi'ers from standard nuts as to its base it and in being provided with a slot l2. The bore of the nut is indicated at It, and the base of the nut from the point M to the edge l5 lies in a plane at right-angles to the axis of the bore. The base of the nut, however, slopes downwardly from the point id to the outer edge It which is rounded, so that when the nut is screwed down, the part It will contact first for a. purpose which will now appear.

0n the same side of the nut as the part it, I provide the stepped slot i2, which enters the nut 5 from the lower part thereof and is directed obliquely upwardly to a point H which is past the axis of the nut. The slot may be comparatively narrow at its inner part, and is provided with a shoulder it whereby the slot is wider at the outer 46 of the nut than at the inner.

(in Fig. 2, I illustrate the nut it applied to the ed end it of a bolt 20 against a work surface or other suitably supported element at. As the nut is turned down, the part i6 contacts first with the element 2!, and as it is turned further, it becomes necesary for the part of the nut which is below the slot to bend upwardly with respect to the rest or the nut, and this is permitted by the slot. As a result, the threads below the slot are given a clamping action when the nut is forced tightly into position.

I make my nuts of a material which is well adapted to the functions and purposes above indicated. This material should be strong and 55 tough, having sufllcient resiliency to cause the Russura bending or locking action required, yet not be subject to permanent deformation by being used.

It should be of such a character as to be easily milled or cut in order that the slotting operation may be effected at minimum cost, and it should 5 also respond properly to the process of hardening. The material should be such that the threads may be thrown out of alignment by the normal use of the nut, and then returned to exact alignment when the nut is removed from the work so that 10 the nut may be used again. The nut may be made of any suitable material having the aboveindicated character, and I have found that steels having a carbon content of about 0.4% to 0.6% are well'adapted for this purpose, and that of 15 these the best results are obtained when the car-- bon content runs about 0.5% to 0.6%.

In the manufacture of the nuts I ordinarily start with flat bars from which the nut-blanks may be made, preferably by hot-forging algo though other methods, such as cold pun and rolling, are well adapted to the purpose. In making these blanks the base or the nut is given the peculiar shape above described. The slots may be produced by cutting, breaching, milling, gs or any other suitable method, and this slotting may be performed cold.

After slotting, the blank is 1 threads are cut interiorally in the bore, and it is important that the slotting operation precede so the tapping operation in order to avoid damage to the threads, which may occur it the nut be slotted after the threads are present.

Thereafter the nuts are hardened by heating,

drawing and quenching in order to develop the as required resiliency or springiness therein; and

this must be so great that the slot will re-open to its normal position on removm oi the nut from the work, or at least as nearly so as is required to re-align the threads to their normal align- 4o ment, even after the slot has been entirely closed by pressure.

when the stel above described is used, the

hardening is best to a point within the range of 255 to 302 on the Brinnell scale of hardness, al- 45 though some variation above or'below this range is still useful.

I have referred to various details by way oi illustration, but it is to be understood that various changes may be made without departing from 50 the spirit of the invention the scope of which is defined in the appended claims.

Having described my invention, what I claim and desire to secure by Letters Patent lat-- 1. The method of making a spring nut which containing about 0.4% to 0.6% carbon, then hotforging the bar to the desired shape of the nut and forming the nut blank, then slotting the nut blank and subsequently thereto tapping the nut blank, and finally hardening the nut by a, heating, drawing end quenching operation to n degree equivalent to n Brlnnell :1 tan test which lies 'within a, renge oomprinngthe range of 255 to 302.

2-. The method of trunking a spring nut which consists in first utilizing for this purpose a bar of steel of a, strong, tough, tree milling nature containing about 0.5% to 0.6% carbon, then hotiorging the bar to the desired shape of the nut and running the nut blank, then slotting the nut blank and subsequently thereto tapping the nut blank, and finally hnrdening the nut by a heating, drawing and. quenching operation to a degree equivalent to e. Brinnell hardness tat of about 255 to 36$. 7

m: A. BmGSTROM. 

